Pub Date : 2025-12-08DOI: 10.1515/nanoph-2025-0429
Alessandra Sabatti, Jost Kellner, Robert J. Chapman, Rachel Grange
Nonlinear frequency conversion offers powerful capabilities for applications in telecommunications, signal processing, and computing. Thin-film lithium niobate (TFLN) has emerged as a promising integrated photonics platform due to its strong electro-optic effect and second-order nonlinearity, which can be exploited through periodic poling. However, conventional poling techniques in x-cut TFLN are constrained to minimum period sizes on the order of microns, restricting access to highly phase-mismatched interactions such as counter- and backward-propagating frequency conversion. In this work, we demonstrate scalable periodic poling of x-cut TFLN with domains periods as short as 215 nm and realize devices that support both counter- and back-propagating phase matching. We estimate conversion efficiencies of 1,474 %/W/cm 2 and 45 %/W/cm 2 for the two interaction types, respectively. Sum frequency generation measurements confirm that the nonlinear generation takes place in the desired direction. Furthermore, we report spontaneous parametric down conversion for the counter-propagating configuration and, for the first time, for a backward propagating device. This breakthrough provides unprecedented control over engineering of ferroelectric domain geometries in TFLN, leading into the generation of photon pairs with precisely tailored spatial and spectral characteristics. Such capabilities hold strong potential for advancing quantum signal processing, scalable quantum computing architectures, and precision quantum metrology.
{"title":"Nanodomain poling unlocking backward nonlinear light generation in thin film lithium niobate","authors":"Alessandra Sabatti, Jost Kellner, Robert J. Chapman, Rachel Grange","doi":"10.1515/nanoph-2025-0429","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0429","url":null,"abstract":"Nonlinear frequency conversion offers powerful capabilities for applications in telecommunications, signal processing, and computing. Thin-film lithium niobate (TFLN) has emerged as a promising integrated photonics platform due to its strong electro-optic effect and second-order nonlinearity, which can be exploited through periodic poling. However, conventional poling techniques in x-cut TFLN are constrained to minimum period sizes on the order of microns, restricting access to highly phase-mismatched interactions such as counter- and backward-propagating frequency conversion. In this work, we demonstrate scalable periodic poling of x-cut TFLN with domains periods as short as 215 nm and realize devices that support both counter- and back-propagating phase matching. We estimate conversion efficiencies of 1,474 %/W/cm <jats:sup>2</jats:sup> and 45 %/W/cm <jats:sup>2</jats:sup> for the two interaction types, respectively. Sum frequency generation measurements confirm that the nonlinear generation takes place in the desired direction. Furthermore, we report spontaneous parametric down conversion for the counter-propagating configuration and, for the first time, for a backward propagating device. This breakthrough provides unprecedented control over engineering of ferroelectric domain geometries in TFLN, leading into the generation of photon pairs with precisely tailored spatial and spectral characteristics. Such capabilities hold strong potential for advancing quantum signal processing, scalable quantum computing architectures, and precision quantum metrology.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"22 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-08DOI: 10.1515/nanoph-2025-0512
Yasuhiro Tamayama, Yugo Shibata
We propose and validate a method for designing a broadband variable beamsplitter using a metamaterial with subwavelength thickness. Through theoretical analysis and numerical simulations, we demonstrate that the reflectance-to-transmittance ratio of a single-layer resonant metamaterial at its resonance frequency can be controlled by varying the spatial arrangement of the constituent meta-atoms, without altering their individual structures. Building on this theory, we further conjecture a method for achieving a frequency-independent reflectance-to-transmittance ratio across a broad spectral range. Numerical results confirm that a metamaterial with subwavelength thickness can be engineered to function as a broadband variable beamsplitter using the proposed approach. These findings contribute to the advancement of techniques for splitting and combining electromagnetic waves in compact systems.
{"title":"Broadband variable beamsplitter made of a subwavelength-thick metamaterial","authors":"Yasuhiro Tamayama, Yugo Shibata","doi":"10.1515/nanoph-2025-0512","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0512","url":null,"abstract":"We propose and validate a method for designing a broadband variable beamsplitter using a metamaterial with subwavelength thickness. Through theoretical analysis and numerical simulations, we demonstrate that the reflectance-to-transmittance ratio of a single-layer resonant metamaterial at its resonance frequency can be controlled by varying the spatial arrangement of the constituent meta-atoms, without altering their individual structures. Building on this theory, we further conjecture a method for achieving a frequency-independent reflectance-to-transmittance ratio across a broad spectral range. Numerical results confirm that a metamaterial with subwavelength thickness can be engineered to function as a broadband variable beamsplitter using the proposed approach. These findings contribute to the advancement of techniques for splitting and combining electromagnetic waves in compact systems.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-08DOI: 10.1515/nanoph-2025-0515
Juwon Jung, Leeju Hwang, Nagyeong Kim, Kibaek Kim, Seri Kim, Jongkyoon Park, Won Chegal, Yong Jai Cho, Young-Joo Kim
Spectroscopic ellipsometry (SE) is a powerful, non-destructive technique for nanoscale structural characterization. However, conventional SE data analysis typically assumes perfectly periodic specimen structures, overlooking fabrication-induced structural variations and thereby reducing the accuracy of predicted structural parameters. We have developed an enhanced analysis framework that explicitly accounts for both nanoscale structural variations and measurement-angle misalignment by introducing the concept of an average Mueller matrix (MM), which represents statistical distributions of nanoscale structures. In addition, we introduce a high-throughput MM-generation neural network that enables rapid data preparation by approximating rigorous coupled-wave analysis (RCWA) simulations for large numbers of specimens across a broad range of structural parameters. The model achieves a mean-squared error of 9.99 × 10 −8 MSE when validated against RCWA-simulated MM data for one-dimensional SiO 2 nanogratings. Finally, we apply our analysis framework to experimentally measured MM data, achieving highly accurate dimensional predictions with errors below 0.4 nm when compared with structural parameters measured by scanning electron microscopy (SEM). We believe that this analysis algorithm significantly advances the potential for high-precision SE-based metrology in semiconductor, photonic, and display manufacturing.
{"title":"AI-based analysis algorithm incorporating nanoscale structural variations and measurement-angle misalignment in spectroscopic ellipsometry","authors":"Juwon Jung, Leeju Hwang, Nagyeong Kim, Kibaek Kim, Seri Kim, Jongkyoon Park, Won Chegal, Yong Jai Cho, Young-Joo Kim","doi":"10.1515/nanoph-2025-0515","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0515","url":null,"abstract":"Spectroscopic ellipsometry (SE) is a powerful, non-destructive technique for nanoscale structural characterization. However, conventional SE data analysis typically assumes perfectly periodic specimen structures, overlooking fabrication-induced structural variations and thereby reducing the accuracy of predicted structural parameters. We have developed an enhanced analysis framework that explicitly accounts for both nanoscale structural variations and measurement-angle misalignment by introducing the concept of an average Mueller matrix (MM), which represents statistical distributions of nanoscale structures. In addition, we introduce a high-throughput MM-generation neural network that enables rapid data preparation by approximating rigorous coupled-wave analysis (RCWA) simulations for large numbers of specimens across a broad range of structural parameters. The model achieves a mean-squared error of 9.99 × 10 <jats:sup>−8</jats:sup> MSE when validated against RCWA-simulated MM data for one-dimensional SiO <jats:sub>2</jats:sub> nanogratings. Finally, we apply our analysis framework to experimentally measured MM data, achieving highly accurate dimensional predictions with errors below 0.4 nm when compared with structural parameters measured by scanning electron microscopy (SEM). We believe that this analysis algorithm significantly advances the potential for high-precision SE-based metrology in semiconductor, photonic, and display manufacturing.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"134 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-08DOI: 10.1515/nanoph-2025-0456
Joshua T. Y. Tse, Taisuke Enomoto, Shunsuke Murai, Katsuhisa Tanaka
Bound states in the continuum (BIC) exhibit extremely high quality factors due to the lack of radiation loss and thus are widely studied for Purcell enhancement. However, a closer examination reveals that the enhancement is absent at the BIC due to the lack of out-coupling capability, but the strong enhancement is only observed at nearby configuration, namely quasi -BIC. To study this unique behavior of the Purcell enhancement near BIC, we built an analytical model with spectral parameters to analyze the Purcell enhancement on metasurfaces supporting quasi -BIC. Our analytical model predicts the average Purcell enhancement by metasurfaces coupled to a luminescent medium, utilizing parameters that are formulated through the temporal coupled-mode theory and can be derived from measured spectra such as transmissivity and reflectivity. We analyzed several metasurfaces supporting quasi -BIC numerically and experimentally to study the behavior of the spectral parameters as well as the resultant Purcell enhancement. We formulated the interdependence between the quality factor and the out-coupling efficiency, and revealed the existence of optimal detuning from the BIC. We also discovered that our findings are general and applicable towards realistic metasurfaces that are lossy and/or asymmetric. This discovery provides an intuitive model to understand the modal qualities of quasi -BIC and will facilitate optimization of quasi -BIC for luminescence enhancement applications.
{"title":"Modelling Purcell enhancement of metasurfaces supporting quasi -bound states in the continuum","authors":"Joshua T. Y. Tse, Taisuke Enomoto, Shunsuke Murai, Katsuhisa Tanaka","doi":"10.1515/nanoph-2025-0456","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0456","url":null,"abstract":"Bound states in the continuum (BIC) exhibit extremely high quality factors due to the lack of radiation loss and thus are widely studied for Purcell enhancement. However, a closer examination reveals that the enhancement is absent at the BIC due to the lack of out-coupling capability, but the strong enhancement is only observed at nearby configuration, namely <jats:italic>quasi</jats:italic> -BIC. To study this unique behavior of the Purcell enhancement near BIC, we built an analytical model with spectral parameters to analyze the Purcell enhancement on metasurfaces supporting <jats:italic>quasi</jats:italic> -BIC. Our analytical model predicts the average Purcell enhancement by metasurfaces coupled to a luminescent medium, utilizing parameters that are formulated through the temporal coupled-mode theory and can be derived from measured spectra such as transmissivity and reflectivity. We analyzed several metasurfaces supporting <jats:italic>quasi</jats:italic> -BIC numerically and experimentally to study the behavior of the spectral parameters as well as the resultant Purcell enhancement. We formulated the interdependence between the quality factor and the out-coupling efficiency, and revealed the existence of optimal detuning from the BIC. We also discovered that our findings are general and applicable towards realistic metasurfaces that are lossy and/or asymmetric. This discovery provides an intuitive model to understand the modal qualities of <jats:italic>quasi</jats:italic> -BIC and will facilitate optimization of <jats:italic>quasi</jats:italic> -BIC for luminescence enhancement applications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"208 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-06DOI: 10.1515/nanoph-2025-0468
Mikhail K. Tatmyshevskiy, Georgy A. Ermolaev, Dmitriy V. Grudinin, Aleksandr S. Slavich, Nikolay V. Pak, Marwa A. El-Sayed, Alexander Melentev, Elena Zhukova, Roman I. Romanov, Dmitry I. Yakubovsky, Andrey A. Vyshnevyy, Sergey M. Novikov, Aleksey V. Arsenin, Valentyn S. Volkov
van der Waals transition metal dichalcogenides, distinguished by a high refractive index and giant optical anisotropy, are promising materials for integrated photonic devices. However, their superior optical properties are nowadays limited to exfoliated samples with only a micrometer scale, whereas industrial integration requires at least cm-scale dimensions. Here, we resolve this problem for MoTe 2 by demonstrating that chemical vapor deposition synthesis can provide an identical optical response to the benchmark exfoliated samples in a broad spectral range (250–5,000 nm). It allows us to show high-performance waveguiding properties of MoTe 2 with a subwavelength footprint of ∼ λ /8 for telecommunication wavelengths. Therefore, our findings reveal MoTe 2 as an ideal platform for the next-generation nanophotonics.
{"title":"Bridging the scalability gap in van der Waals light guiding with high refractive index MoTe 2","authors":"Mikhail K. Tatmyshevskiy, Georgy A. Ermolaev, Dmitriy V. Grudinin, Aleksandr S. Slavich, Nikolay V. Pak, Marwa A. El-Sayed, Alexander Melentev, Elena Zhukova, Roman I. Romanov, Dmitry I. Yakubovsky, Andrey A. Vyshnevyy, Sergey M. Novikov, Aleksey V. Arsenin, Valentyn S. Volkov","doi":"10.1515/nanoph-2025-0468","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0468","url":null,"abstract":"van der Waals transition metal dichalcogenides, distinguished by a high refractive index and giant optical anisotropy, are promising materials for integrated photonic devices. However, their superior optical properties are nowadays limited to exfoliated samples with only a micrometer scale, whereas industrial integration requires at least cm-scale dimensions. Here, we resolve this problem for MoTe <jats:sub>2</jats:sub> by demonstrating that chemical vapor deposition synthesis can provide an identical optical response to the benchmark exfoliated samples in a broad spectral range (250–5,000 nm). It allows us to show high-performance waveguiding properties of MoTe <jats:sub>2</jats:sub> with a subwavelength footprint of ∼ <jats:italic>λ</jats:italic> /8 for telecommunication wavelengths. Therefore, our findings reveal MoTe <jats:sub>2</jats:sub> as an ideal platform for the next-generation nanophotonics.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"27 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145680050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1515/nanoph-2025-0487
Joonyoung Kim, Gangseon Ji, Hyoung-Taek Lee, Jeonghoon Kim, Han-Seok Park, Uksam Choi, Choongwon Seo, Changhee Sohn, Kyungwan Kim, Byeongwon Kang, Hyeong-Ryeol Park
Superconductivity collapses when all Cooper pairs acquire energies exceeding the superconducting gap. Breaking these pairs requires photons with energy greater than the superconducting gap or strong terahertz (THz) electric fields, which has limited the practical use of superconducting devices at THz frequencies. Here, we show that GdBa 2 Cu 3 O 7-δ (GdBCO) film integrated with 15-nm metal nanogaps exhibit Cooper pair breaking at 20 K, which is lower than its critical temperature Tc , under incident THz fields as low as 60 V/cm. It should be noted that the extracted optical constants of the nanogap-integrated film exhibit a characteristic of a non-superconducting state, in contrast to the bare GdBCO film. This suppression of the superconductivity cannot be attributed to heating or fabrication damage but instead arises from the nanogap-enhanced THz fields delivering ponderomotive energy beyond the superconducting gap. Our results establish a non-thermal, low-field pathway for controlling superconductivity, opening opportunities for highly sensitive superconducting optoelectronic devices such as a THz single photon detector.
当所有库珀对获得的能量超过超导间隙时，超导性就会崩溃。打破这些对需要能量大于超导间隙或强太赫兹（THz）电场的光子，这限制了在太赫兹频率下超导设备的实际使用。本文表明，在低至60 V/cm的入射太赫兹场下，集成了15 nm金属纳米隙的GdBa 2 Cu 3 O 7-δ (GdBCO)薄膜在20 K时出现库珀对断裂，低于其临界温度T c。值得注意的是，与裸GdBCO膜相比，提取的纳米隙集成膜的光学常数表现出非超导状态的特征。这种对超导性的抑制不能归因于加热或制造损坏，而是由于纳米隙增强的太赫兹场在超导隙之外提供了重动力能量。我们的研究结果为控制超导性建立了一种非热、低场途径，为高灵敏度超导光电器件（如太赫兹单光子探测器）开辟了机会。
{"title":"Nanogap-enhanced terahertz suppression of superconductivity","authors":"Joonyoung Kim, Gangseon Ji, Hyoung-Taek Lee, Jeonghoon Kim, Han-Seok Park, Uksam Choi, Choongwon Seo, Changhee Sohn, Kyungwan Kim, Byeongwon Kang, Hyeong-Ryeol Park","doi":"10.1515/nanoph-2025-0487","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0487","url":null,"abstract":"Superconductivity collapses when all Cooper pairs acquire energies exceeding the superconducting gap. Breaking these pairs requires photons with energy greater than the superconducting gap or strong terahertz (THz) electric fields, which has limited the practical use of superconducting devices at THz frequencies. Here, we show that GdBa <jats:sub>2</jats:sub> Cu <jats:sub>3</jats:sub> O <jats:sub>7-δ</jats:sub> (GdBCO) film integrated with 15-nm metal nanogaps exhibit Cooper pair breaking at 20 K, which is lower than its critical temperature <jats:italic>T</jats:italic> <jats:sub>c</jats:sub> , under incident THz fields as low as 60 V/cm. It should be noted that the extracted optical constants of the nanogap-integrated film exhibit a characteristic of a non-superconducting state, in contrast to the bare GdBCO film. This suppression of the superconductivity cannot be attributed to heating or fabrication damage but instead arises from the nanogap-enhanced THz fields delivering ponderomotive energy beyond the superconducting gap. Our results establish a non-thermal, low-field pathway for controlling superconductivity, opening opportunities for highly sensitive superconducting optoelectronic devices such as a THz single photon detector.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145673590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1515/nanoph-2025-0427
Lukas Freter, Piper Fowler-Wright, Javier Cuerda, Brendon W. Lovett, Jonathan Keeling, Päivi Törmä
We develop the theory of dynamical superradiance – the collective exchange of energy between an ensemble of initially excited emitters and a single-mode cavity – for organic materials where electronic states are coupled to vibrational modes. We consider two models to capture the vibrational effects: first, vibrations treated as a Markovian bath for two-level emitters, via a pure dephasing term in the Lindblad master equation for the system; second, vibrational modes directly included in the system via the Holstein–Tavis–Cummings Hamiltonian. By exploiting the permutation symmetry of the emitters and weak U(1) symmetry, we develop a numerical method capable of exactly solving the Tavis–Cummings model with local dissipation for up to 140 emitters. Using the exact method, we validate mean-field and second-order cumulant approximations and use them to describe macroscopic numbers of emitters. We analyze the dynamics of the average cavity photon number, electronic coherence, and Bloch vector length and show that the effect of vibrational mode coupling goes beyond simple dephasing. Our results show that superradiance is possible in the presence of vibrational mode coupling; for negative cavity detunings, the vibrational coupling may even enhance superradiance. We identify asymmetry of the photon number rise time as a function of the detuning of the cavity frequency as an experimentally accessible signature of such vibrationally assisted superradiance.
{"title":"Theory of dynamical superradiance in organic materials","authors":"Lukas Freter, Piper Fowler-Wright, Javier Cuerda, Brendon W. Lovett, Jonathan Keeling, Päivi Törmä","doi":"10.1515/nanoph-2025-0427","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0427","url":null,"abstract":"We develop the theory of dynamical superradiance – the collective exchange of energy between an ensemble of initially excited emitters and a single-mode cavity – for organic materials where electronic states are coupled to vibrational modes. We consider two models to capture the vibrational effects: first, vibrations treated as a Markovian bath for two-level emitters, via a pure dephasing term in the Lindblad master equation for the system; second, vibrational modes directly included in the system via the Holstein–Tavis–Cummings Hamiltonian. By exploiting the permutation symmetry of the emitters and weak U(1) symmetry, we develop a numerical method capable of exactly solving the Tavis–Cummings model with local dissipation for up to 140 emitters. Using the exact method, we validate mean-field and second-order cumulant approximations and use them to describe macroscopic numbers of emitters. We analyze the dynamics of the average cavity photon number, electronic coherence, and Bloch vector length and show that the effect of vibrational mode coupling goes beyond simple dephasing. Our results show that superradiance is possible in the presence of vibrational mode coupling; for negative cavity detunings, the vibrational coupling may even enhance superradiance. We identify asymmetry of the photon number rise time as a function of the detuning of the cavity frequency as an experimentally accessible signature of such vibrationally assisted superradiance.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"29 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1515/nanoph-2025-0500
Arieh Grosman, Roy Zektzer, Noa Mazurski, Liron Stern, Uriel Levy
Atom-based technologies have played a central role in both fundamental research and application-driven developments. For example, devices such as atomic clocks and magnetometers are essential for precision time-keeping, navigation, and sensing. However, many of these demonstrations remain confined to laboratory settings due to their reliance on bulky equipment and centimeter-scale atomic vapor cells. In recent years, significant efforts have been made to miniaturize these vapor cells to enable field-deployable systems. Yet, integrating these cells with the necessary photonic components remains a complex and non-scalable process. To address this challenge, we have introduced the atomic-cladded waveguide (ACWG) architecture, which enables the integration of atomic and photonic functions on the same chip. While the ACWG concept provides a significant step forward toward integration, there is still a significant gap related to wafer scale manufacturability. In particular, previous demonstrations of atomic–photonic integration have relied on manual assembly of vapor cells onto single chips, restricting miniaturization, manufacturability, and thermal robustness. To revolutionize manufacturability of these devices, we hereby demonstrate our new generation of ACWG devices that overcomes these constraints. The approach is based on wafer bonding of a silicon wafer – consisting of multiple photonic chips to a glass wafer with pre-etched atomic chambers. This wafer-scale process yields multiple miniaturized integrated photonic–atomic chips in a single batch. The bonded devices operate reliably at elevated temperatures over an extended period of time, allowing higher atomic densities to be used. The fabrication method consists of well-defined, repeatable steps, paving the way for scalable production of mature integrated photonic–atomic systems for next-generation sensing, metrology, and quantum technologies, inspired by commercial complementary metal-oxide-semiconductor-based processes.
{"title":"Wafer-scale integration of photonic integrated circuits and atomic vapor cells","authors":"Arieh Grosman, Roy Zektzer, Noa Mazurski, Liron Stern, Uriel Levy","doi":"10.1515/nanoph-2025-0500","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0500","url":null,"abstract":"Atom-based technologies have played a central role in both fundamental research and application-driven developments. For example, devices such as atomic clocks and magnetometers are essential for precision time-keeping, navigation, and sensing. However, many of these demonstrations remain confined to laboratory settings due to their reliance on bulky equipment and centimeter-scale atomic vapor cells. In recent years, significant efforts have been made to miniaturize these vapor cells to enable field-deployable systems. Yet, integrating these cells with the necessary photonic components remains a complex and non-scalable process. To address this challenge, we have introduced the atomic-cladded waveguide (ACWG) architecture, which enables the integration of atomic and photonic functions on the same chip. While the ACWG concept provides a significant step forward toward integration, there is still a significant gap related to wafer scale manufacturability. In particular, previous demonstrations of atomic–photonic integration have relied on manual assembly of vapor cells onto single chips, restricting miniaturization, manufacturability, and thermal robustness. To revolutionize manufacturability of these devices, we hereby demonstrate our new generation of ACWG devices that overcomes these constraints. The approach is based on wafer bonding of a silicon wafer – consisting of multiple photonic chips to a glass wafer with pre-etched atomic chambers. This wafer-scale process yields multiple miniaturized integrated photonic–atomic chips in a single batch. The bonded devices operate reliably at elevated temperatures over an extended period of time, allowing higher atomic densities to be used. The fabrication method consists of well-defined, repeatable steps, paving the way for scalable production of mature integrated photonic–atomic systems for next-generation sensing, metrology, and quantum technologies, inspired by commercial complementary metal-oxide-semiconductor-based processes.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"129 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Precise manipulation of Bragg reflection in cholesteric liquid crystals (CLCs) is essential for advancing reconfigurable optics. However, existing photo-responsive material-doped CLC technologies that rely on single-wavelength photoisomerization encounter several challenges, including slow response times, limited tunability, inadequate spatial control, and instability caused by pitch variations due to diffusion. Here, we present a robust dual-wavelength photoisomerization method to simultaneously achieve trans -to- cis and cis -to- trans photoisomerization of chiral azobenzene-doped CLCs, which enables broadband, reversible, and spatially addressable control over the Bragg reflection spectrum. By employing counterpropagating laser beams at 405 nm and 532 nm, we precisely control the trans – cis isomerization dynamics of azobenzene chiral dopants, achieving spectral shifts exceeding 100 nm primarily through reversible modulation of the helical pitch of the CLCs. Furthermore, manipulating the intensity ratio and geometry of the excitation beams allows for tailored pitch gradients, reflection bandwidths, and central wavelengths with remarkable fidelity. Our approach enhances pitch boundaries and reduces molecular diffusion, facilitating the micrometer-scale patterning of optical textures, which surpasses traditional single-wavelength methods. Additionally, we present an innovative narrowband spectral filtering technique by sequentially transmitting light through pitch-selective CLC regions under circular polarization control. This reconfigurable manipulation strategy paves the way for developing programmable photonic systems, including adaptive optics, diffractive optics, and tunable displays.
{"title":"Light-guided spectral sculpting in chiral azobenzene-doped cholesteric liquid crystals for reconfigurable narrowband unpolarized light sources","authors":"Pravinraj Selvaraj, Ming-Hong Yuan, Cheng-Kai Liu, Ko-Ting Cheng","doi":"10.1515/nanoph-2025-0455","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0455","url":null,"abstract":"Precise manipulation of Bragg reflection in cholesteric liquid crystals (CLCs) is essential for advancing reconfigurable optics. However, existing photo-responsive material-doped CLC technologies that rely on single-wavelength photoisomerization encounter several challenges, including slow response times, limited tunability, inadequate spatial control, and instability caused by pitch variations due to diffusion. Here, we present a robust dual-wavelength photoisomerization method to simultaneously achieve <jats:italic>trans</jats:italic> -to- <jats:italic>cis</jats:italic> and <jats:italic>cis</jats:italic> -to- <jats:italic>trans</jats:italic> photoisomerization of chiral azobenzene-doped CLCs, which enables broadband, reversible, and spatially addressable control over the Bragg reflection spectrum. By employing counterpropagating laser beams at 405 nm and 532 nm, we precisely control the <jats:italic>trans</jats:italic> – <jats:italic>cis</jats:italic> isomerization dynamics of azobenzene chiral dopants, achieving spectral shifts exceeding 100 nm primarily through reversible modulation of the helical pitch of the CLCs. Furthermore, manipulating the intensity ratio and geometry of the excitation beams allows for tailored pitch gradients, reflection bandwidths, and central wavelengths with remarkable fidelity. Our approach enhances pitch boundaries and reduces molecular diffusion, facilitating the micrometer-scale patterning of optical textures, which surpasses traditional single-wavelength methods. Additionally, we present an innovative narrowband spectral filtering technique by sequentially transmitting light through pitch-selective CLC regions under circular polarization control. This reconfigurable manipulation strategy paves the way for developing programmable photonic systems, including adaptive optics, diffractive optics, and tunable displays.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"118 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145665029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We demonstrate a temperature-insensitive high- Q tantalum oxide (Ta 2 O 5 ) microdisk resonator fabricated using electron-beam lithography and inductively coupled plasma reactive-ion etching. The microdisks exhibit a loaded Q -factor of 4.25 × 10 5 at 1,550 nm, which more than doubles (∼9.3 × 10 5 ) following thermal annealing at 600 °C. Remarkably, the temperature-dependent resonant wavelength shift is suppressed to less than 10 pm/°C across a broad 100 nm bandwidth. Furthermore, the resonators maintain high optical stability under elevated input powers, with no observed degradation in optical properties such as extinction ratio or Q -factor. The combination of high Q -factors and exceptional thermal stability positions the Ta 2 O 5 microdisk resonators as a promising platform for integrated photonic device applications, including on-chip narrow-linewidth lasers and precision sensing.
{"title":"Monolithic temperature-insensitive high- Q Ta 2 O 5 microdisk resonator","authors":"Zhen Yang, Zheng Zhang, Peng Cheng, Zhe Long, Qi Cheng, Jiaqi Yang, Yu Lin, Bin Fang, Zhongming Zeng, Zhiping Zhou, Ganapathy Senthil Murugan, Rongping Wang","doi":"10.1515/nanoph-2025-0485","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0485","url":null,"abstract":"We demonstrate a temperature-insensitive high- <jats:italic>Q</jats:italic> tantalum oxide (Ta <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> ) microdisk resonator fabricated using electron-beam lithography and inductively coupled plasma reactive-ion etching. The microdisks exhibit a loaded <jats:italic>Q</jats:italic> -factor of 4.25 × 10 <jats:sup>5</jats:sup> at 1,550 nm, which more than doubles (∼9.3 × 10 <jats:sup>5</jats:sup> ) following thermal annealing at 600 °C. Remarkably, the temperature-dependent resonant wavelength shift is suppressed to less than 10 pm/°C across a broad 100 nm bandwidth. Furthermore, the resonators maintain high optical stability under elevated input powers, with no observed degradation in optical properties such as extinction ratio or <jats:italic>Q</jats:italic> -factor. The combination of high <jats:italic>Q</jats:italic> -factors and exceptional thermal stability positions the Ta <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> microdisk resonators as a promising platform for integrated photonic device applications, including on-chip narrow-linewidth lasers and precision sensing.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"156 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145673591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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